ATI Radeon HD 2900 XT Video Card ReviewMon, May 14, 2007 - 12:00 AM
The ATI HD 2900 XT Up Close
The ATI Radeon HD 2900 XT can be used in crossfire as seen above in one of our test platforms. Two internal ATI CrossFire bridge interconnects link the two cards together for those that have a motherboard that has two PCI Express x16 slots and enough money to pick up a pair of these cards. ATI informed us that future Catalyst drivers will default to Alternate Frame Rendering (AFR) mode to help give consumers better performance with no need to change the settings in the Catalyst Control Center.
The core on the Radeon HD 2900 XT is clocked at 743MHz and its 512MB of GDDR3 RAM is clocked at 825MHz (1.66GHz DDR). At these frequencies that card has a theoretical peak pixel processing rate of 47.5 Gigapixels/sec and a peak triangle processing rate of 742M triangles/s. The Radeon HD 2900 XT also has up to 106GB/s of memory bandwidth thanks to its 512-bit memory interface. All of this processing power requires ~215W per card and a large copper heat pipe covers most of the card to help keep it nice and cool. The flame stickers on the fan shroud add a nice touch to something that would have looked a bit plain without them.
The ATI HD 2900 XT video card comes with a 6-pin and an 8-pin pair of power connectors. When running the HD 2900 XT at stock frequiences only a pair of 6-pin power heards need to be used. When overclocking it’s highly suggest to use a 6-pin and an 8-pin power cable to make sure the video card has enough power. When overclocked the HD 2900 XT uses more than 220W at full load, which is a healthy amount of power. When an 8+6 pin PSU is plugged in, the software detects it and allows the card to be “tuned” up. By using “OverDrive” (the name of ATI’s “tuning” feature in Catalyst Control Center) end users are able to mildly overclock the video card. For those that want to really push the limits of the card we encourage you to take a look at a tool called PowerStrip. The latest PowerStrip can be downloaded here.
All Radeon HD 2900 XT cards are equipped with dual, dual-link DVI outputs with HDCP support. An ATI Theater 200 chip with feature ViVo functionality is also found on the graphics card. The rear of the card has a heat spreader that helps keep the memory chips cool.
Just for fun we removed the rear heat spreader as seen above to check out what memory IC’s that ATI put on the initial batch of engineering samples.
With the heat spreader removed the name Hynix and part number HY5RS573225AFP-1 could easily be seen. These GDDR3 memory IC’s have a clock frequency of 1000MHz (2GHz DDR), which means these IC’s can do far more than the 825MHz (1.66GHz DDR) that ATI has the Radeon HD 2900 XT clocked at. This could be a good sign that the HD 2900 XT is a great overclocker, but remember you have to have both the 8-pin and a 6-pin power connectors in use to overclock it!